Note: The GTX 335/345 can only be sold to experimental aircraft. Certified aircraft must purchase this unit from a shop certified by Garmin to perform installations.

All-inclusive 1090 MHz ADS-B “Out” Transponder Solution

Satisfies NextGen equipage requirements for ADS-B “Out”

1090 MHz output enables aircraft to operate at any altitude, in airspace around the globe

Combines Mode S Extended Squitter (ES) transponder and optional WAAS/GPS position source in a single unit

Useful display features include flight time, count-up and count-down timers, plus current pressure altitude readout

Easy replacement for your existing transponder, with common 1.65-inch tall form factor

For aircraft operators looking to satisfy the ADS-B “Out” equipage rules as quickly and cost-effectively as possible, the Garmin GTX 335 ES transponder offers the ideal one-box, one-swap solution. It’s optionally available with a built-in WAAS GPS position source – so everything needed to meet compliance standards for a certified ADS-B “Out” solution can be provided with this simple all-in-one package installation.

The Inside Track to ADS-B “Out”
With more fielded ADS-B solutions than any other brand in the industry, Garmin is committed to making the transition to NextGen airspace as simple and straightforward as possible. The IFR-certified GTX 335 is a prime example. It looks and operates like a standard Mode S transponder. It fits in the same 1.65-inch high slot in your avionics stack. It boasts a digital display, a pressure altitude readout, and dedicated pushbuttons numbered 0-9 for quick and easy squawk code entry. Plus, it’s an all solid-state design, which makes for lower power consumption and enhanced reliability, compared to earlier-generation transponder technology. What’s more, the addition of 1090 MHz ADS-B “Out” transmission capability (using precise GPS-referenced positioning information) enables the GTX 335 to automatically output more accurate, and more useful, traffic surveillance data to ATC – including aircraft flight ID, position, altitude, velocity, climb/descent, and heading information. Conventional Mode S and Mode C transponders can only broadcast altitude and squawk code – which means they require ground-based radar to correlate and identify the aircraft’s position on the controller’s radar screen.

Enhanced Traffic Surveillance
Using 1090 MHz extended squitter ADS-B “Out” transmission, the Garmin GTX 335 improves upon the existing transponder query system while working seamlessly with existing ATC protocols. The ADS-B reports provide ground controllers with considerably faster updates than traditional radar. And by simultaneously broadcasting this information to ADS-B “In” display-equipped pilots, it enables them to essentially see the same traffic picture for their location that ATC is watching on the ground.

Leverage Your Existing Avionics
Designed to interface with a wide range of avionics, the GTX 335 enables operators to leverage their existing cockpit equipment to meet ADS-B “Out” requirements with a minimum of cost, downtime and disruption to their panels. The ES transponder’s 1090 MHz ADS-B “Out” signal meets worldwide requirements for flight at any altitude. And, as a size-conforming replacement for many existing Mode S or Mode C transponders, the GTX 335 makes it easy to plug in the NextGen capability you need to the avionics layout you already have. For even more flexibility, optional remote mount GTX versions are available for compatibility with the GTN™ 750/650 series of touchscreen GPS/Comm/Nav systems, as well as select Garmin G1000® integrated flight deck systems – all of which provide built-in remote transponder code selection and control.

Altitude Encoding Made Simple
In addition to its WAAS-enabled position reporting capabilities, the GTX 335R can also be paired with an optional Garmin altitude encoder to satisfy data transmission requirements for IFR. As opposed to other transponders with altitude encoding built in, the Garmin altitude encoder mounts separately on the install rack. So, should the transponder ever require removal, there’s no need for the static line to be disconnected. Which, in turn, eliminates the need for a follow-on leak check, and thus helps minimize ongoing service costs.

An Easier Path to NextGen
For decades Garmin has led in the development and deployment of ADS-B technology. Today, the Garmin GTX 335 series is being FAA approved for installation on hundreds of today’s most popular aircraft makes and models. It’s clear that with the all-in-one GTX 335 solution, Garmin is working to make your transition to ADS-B operations a simple matter of swapping out your transponder.

I currently have a Garmin GTX327 Transponder (since 2003). Is the Garmin GTX 335 pretty much a plug and play, and is this all I would need to meet the requirements for ADS-B? What other items would need to be purchased and installed (antennae, etc.)? What else is needed to get the ADS-B in functionality?
The GTX 335 will require that a new rack, connector kit and backplate be installed. The GTX 335 with GPS is an ADS‐B out compliant, extended squitter, Mode S transponder. The GTX 345 with GPS adds ADS‐B “In” capability, displaying weather and traffic on compatible displays, as well as Garmin Pilot and ForeFlight via Bluetooth®/Connext wireless technology.
Is the Garmin 335/345 a slide-in replacement for a Garmin GTX 327? What additional items/install issues are needed? More antennas?
No, a new rack and connector will need to be installed. The standard 335/345 does not require an extra antenna. The 335/345 with GPS includes an additional GPS antenna.
Is there a version of the Garmin GTX 335/345 with AHRS?
No, the GTX 335 is a transponder with ADS-B Out and the 345 is a transponder with ADS-B In/Out. It does not provide AHRS data.
Do the new Garmin GTX 335 / 345 transponders work with G430W/530W?
Yes. The GTX 335 / 345 will interface with the G430W / G530W.
Will the Garmin GTX 335 trasnponder interface with my GNS 430W & GNS530W for position information? What do I need to add traffic information in to display on the above and a G3X? Assuming the 430W/530W provide the position information and I dont need a GDL 39R for that.
Yes, if you already have a WAAS GPS installed you can order the standard GTX 335 part number 11-14167. This will provide ADS-B out. For ADS-B in to your G3X, you will need the GTX 345 part number 11-14175.
What detailed physical and electrical changes need to be made to replace a GTX327?
A new rack and connector will need to be installed. Wiring will need to be redone, everything will need to be replaced.
I currently have an Aera 796 and ADS-B in GDL-39 3D. Will the GTX 335 meet the ADS-B out requirement and my GDL-39 3D be able to pick up ADS-B in or do I need the GTX 345 to interface correctly for traffic and weather to be displayed on the Aera 796?
Yes, the with GPS option of the GTX 335, part number 11-14169, will provide ADS-B out. You will not need to interface with your 796 as you already have ADS-B in. GTX 335 with GPS along with your current set up of Aera 796 + GDL 39 3D will give you ADS-B in/out.
The GTX 335 comes with the NVG option. What is NVG?
This option has a display approved to be used with night vision goggles. Typical applications include military helicopter, sheriff helicopter, etc. The NVG model does not include GPS.
Does the Garmin GTX 335 with GPS include the mounting tray and GPS Antenna in the purchase price?
Yes, both the rack and GPS antenna are included in the price.
I have a Garmin 330 mode-s installed. I understand the tray must be replaced when installing the GTX 335 with GPS, but are the connections pin compatible, ie power and TIS-B output?
No, the harness will need to be re-wired.
Can the Garmin GTX 335 be upgraded to a GTX 345 at a later date?
No, it cannot.
If I install the 335 in my experimental motor glider myself. How do I program the mode S code number into the 335?
Programming instructions are found under the configuration page in the manual.
Is the antenna included with the Garmin GTX 335 Transponder? If not what antenna is required?
We recommend the ted transponder antenna p/n 11-17995.
Garmin GTX-335, Plan on installing that model. I only have VORs, no GPS. Do I have to go with basic model or GPS GTX-335 to be compliant? Do I need to replace transponder antenna? What harness do I need? And does the small encoder come with the new unit? All my equipment is old.
You would need the GPS option. Your current transponder antenna will work fine, but you would need a separate coaxial cable for the GPS antenna included with the unit. The encoder does not come with the unit, but can be found under p/n 11-14162. We can do either a stock 4ft harness, which fits most needs or a custom if required.
Is a rack & antenna required & / or included in the purchase of a GTX 335 ?
The rack and required antennas are included with the GTX 335. The standard model does not require any external antenna and the with GPS model will include the GPS antenna.
Can the GTX 335 feed traffic to a GNS430 non-WAAS installation or will it only feed to GNS 430W etc?
You will need a GNS 430W to be ADS-B compliant. The GTX 335 is ADS-B Out only and does not have weather/traffic capabilities. Please see the GTX 345 for ADS-B In/Out with weather and traffic.
I currently have a GTX 320A. Will the GTX 335 fit into my current tray?
No it will not. The GTX 335 uses a new rack.
I have a KT76 Mode C transponder. If I purchase this unit will I have to also buy an encoder and the blade antenna?
If replacing a KT76 Mode C transponder with a GTX 335, you would need to purchase the model with GPS to create a full ADS-B out solution which would then include the certified encoder and blade antenna. This PN would be 11-14169.